This investigation will obtain information which relates to the source and cellular function of low molecular weight nuclear (LNA) RNAs which are distinct from transfer, messenger or ribosomal RNAs. Molecular hybridization technology will be used to identify which, if any, complexity classes of DNA in the Novikoff hepatoma cell are enriched for base sequence and which are complementary to LMN RNA. Experiments with inhibitors of the synthesis of specific classes of cellular RNA will be performed to determine if any LMN RNAs are derived from the processing of other classes of nuclear RNA. This information will also help to identify which eukaryote RNA polymerase is responsible for LMN RNA synthesis.